IO Board
16 Bit Digital input, 16 Bit Digital Output.
Outputs
16 Relays
Inputs
16 socketed Optoisolators, rated for 5 to 240 Volts, AC or DC.
Pinout
| Relay board | Signal Name | Pin | # | Pin | Signal Name | ||
|---|---|---|---|---|---|---|---|
| Gnd | Ground | B1 | # | A1 | -I/O CH CK | I/O channel check; active low=parity error | |
| A3,B3 on U21 | RESET DRV | B2 | # | A2 | SD7 | A1 on U24 | |
| +5V | +5 V dc | B3 | # | A3 | SD6 | A2 on U24 | |
| n/c | IRQ 9 | B4 | # | A4 | SD5 | A3 on U24 | |
| n/c | -5 V dc | B5 | # | A5 | SD4 | A4 on U24 | |
| n/c | DRQ2 | B6 | # | A6 | SD3 | A5 on U24 | |
| n/c | -12 V dc | B7 | # | A7 | SD2 | A6 on U24 | |
| n/c | -0WS | B8 | # | A8 | SD1 | A7 on U24 | |
| Connected | +12 V dc | B9 | # | A9 | SD0 | A8 on U24 | |
| Gnd | Ground | B10 | # | A10 | I/O CH RDY | n/c | |
| B2 on U23 - not used | -SMEMW | B11 | # | A11 | AEN | Address enable; active high when DMA controls bus | |
| B1 on U23 - not used | -SMEMR | B12 | # | A12 | SA19 | n/c | |
| A3 on U23 | -IOW | B13 | # | A13 | SA18 | n/c | |
| A4 on U23 | -IOR | B14 | # | A14 | SA17 | n/c | |
| n/c | -DACK3 | B15 | # | A15 | SA16 | n/c | |
| n/c | DRQ3 | B16 | # | A16 | SA15 | n/c | |
| n/c | -DACK1 | B17 | # | A17 | SA14 | n/c | |
| n/c | DRQ1 | B18 | # | A18 | SA13 | n/c | |
| n/c | -REFRESH | B19 | # | A19 | SA12 | n/c | |
| n/c | CLK | B20 | # | A20 | SA11 | n/c | |
| n/c | IRQ7 | B21 | # | A21 | SA10 | n/c | |
| n/c | IRQ6 | B22 | # | A22 | SA9 | A1 on U23 | |
| n/c | IRQ5 | B23 | # | A23 | SA8 | A2 on U23 | |
| n/c | IRQ4 | B24 | # | A24 | SA7 | B4 on U22 | |
| n/c | IRQ3 | B25 | # | A25 | SA6 | B3 on U22 | |
| n/c | -DACK2 | B26 | # | A26 | SA5 | B2 on U22 | |
| n/c | TC | B27 | # | A27 | SA4 | B1 on U22 | |
| n/c | BALE | B28 | # | A28 | SA3 | A4 on U22 | |
| +5V | +5 V dc | B29 | # | A29 | SA2 | A3 on U22 | |
| n/c | OSC | B30 | # | A30 | SA1 | A2 on U22 | |
| Gnd | Ground | B31 | # | A31 | SA0 | A1 on U22 |
IC's
| Label | Chip | Count | Description |
|---|---|---|---|
| HP3700 | 16 | Opto-isolator | |
| ULN2803A | 2 | driver | |
| U27 | 74HC374 | 1 | IP/FLOP OCTAL D-TYPE |
| U17,U28,U35 | HC373 | 3 | LATCH OCTAL 3ST D |
| U16 | HC374 | 1 | FLIP FLOP OCT 3ST |
| U20 | HC138A | 1 | IC DECODER 3-TO-8 LINE |
| U39 | HC688 | 1 | IC COMPARATOR EQUALITY 8B |
| U22,U23 | HCT244A | 2 | IC BUFF/DVR TRI-ST DUAL |
| U21 | HC00A | 1 | IC GATE NAND QUAD 2INP |
| U19 | HC32A | 1 | IC GATE OR QUAD 2INP |
| U38 | 74HC74AM | 1 | F/F W/CLR&SET DUAL D |
| U25 | 74HC4538M | 1 | IC MULTIVIBRATOR DUAL HS |
| U24 | HCT245A | 1 | IC TRANSCVR 8BIT N-INV |